The number of radial nodes for an electron in an orbital is given by:
Radial nodes = n - l - 1,
where:
Only the 6s orbital has five radial nodes. Therefore, the correct answer is 6s.
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 
Two circular discs of radius \(10\) cm each are joined at their centres by a rod, as shown in the figure. The length of the rod is \(30\) cm and its mass is \(600\) g. The mass of each disc is also \(600\) g. If the applied torque between the two discs is \(43\times10^{-7}\) dyne·cm, then the angular acceleration of the system about the given axis \(AB\) is ________ rad s\(^{-2}\).
